Isn’t this an illegal, verging on treasonous, practice in the UK? There’s a 1971 act which would seem to suggest so (unlike in the USA where intent to defraud must be proven). Is there a later one? Who’s the house lawyer?

This is apparently to make it harder to counterfeit, as fake pound coins have been becoming increasingly common over recent years.

I remember when the pound coin was first introduced - before then we had pound notes. The pound coin was thicker than any of the existing coins and I found out that it wouldn’t fit through the slot in the top of my piggy bank.